Model-categories of coalgebras over operads.
Monotone-light factorization for Kan fibrations of simplicial sets with respect to groupoids.
Moore categories.
More about the (co)homology of groups and associative algebras.
Non-abelian cohomology of groups.
Non-abelian cohomology via parity quasi-complexes.
Non-abelian cohomology with coefficients in crossed bimodules.
Noncommutative numerical motives, Tannakian structures, and motivic Galois groups
In this article we further the study of noncommutative numerical motives, initiated in [30, 31]. By exploring the change-of-coefficients mechanism, we start by improving some of the main results of [30]. Then, making use of the notion of Schur-finiteness, we prove that the category NNum of noncommutative numerical motives is (neutral) super-Tannakian. As in the commutative world, NNum is not Tannakian. In order to solve this problem we promote periodic cyclic homology to a well-defined symmetric...
Normalizing the cyclic modules of Connes.
Oka manifolds: From Oka to Stein and back
Oka theory has its roots in the classical Oka-Grauert principle whose main result is Grauert’s classification of principal holomorphic fiber bundles over Stein spaces. Modern Oka theory concerns holomorphic maps from Stein manifolds and Stein spaces to Oka manifolds. It has emerged as a subfield of complex geometry in its own right since the appearance of a seminal paper of M. Gromov in 1989.In this expository paper we discuss Oka manifolds and Oka maps. We describe equivalent characterizations...
On algebraic models for homotopy 3-types.
On derived categories and derived functors.
On long exact -sequences in module theory.
On spaces of the same strong -type.
On the 2-type of an iterated loop space.
On the adjoint map of homotopy abelian DG-Lie algebras
We prove that a differential graded Lie algebra is homotopy abelian if its adjoint map into its cochain complex of derivations is trivial in cohomology. The converse is true for cofibrant algebras and false in general.
On the derivative of the stable homotopy of mapping spaces.
On the derived category of sheaves on a manifold.
On weak -homotopy equivalences of modules
Si definisce il gruppo di —omotopia di un singolo modulo e si introduce la nozione di equivalenza -omotopica debole. Sotto determinate condizioni per l'anello di base oppure per i moduli considerati, le equivalenze -omotopiche deboli coincidono con le equivalenze -omotopiche (forti).
Poincaré duality and commutative differential graded algebras
We prove that every commutative differential graded algebra whose cohomology is a simply-connected Poincaré duality algebra is quasi-isomorphic to one whose underlying algebra is simply-connected and satisfies Poincaré duality in the same dimension. This has applications in rational homotopy, giving Poincaré duality at the cochain level, which is of interest in particular in the study of configuration spaces and in string topology.